Syed Saad Ali
Syed Saad Ali
Oracle Database Material
September 1, 2017
RAC Useful Parameters
Installation/Configurations10gInstallation/Configurations11gInstallation/Configurations12cOracle Database Material
RAC Useful Parameters
| cluster_interconnects | specify a specific IP address to use for the inetrconnect |
| _gcs_fast_config | enables fast reconfiguration for gcs locks (true|false) |
| _lm_master_weight | controls which instance will hold or (re)master more resources than others |
| _gcs_resources | controls the number of resources an instance will master at a time |
| _lm_tickets | controls the number of message tickets |
| _lm_ticket_active_sendback | controls the number of message tickets (aggressive messaging) |
| _db_block_max_cr_dba | limits the number of CR copies per DBA on the buffer cache (see grd) |
| _fairness_threshold | used when too many CR requested arrive for a particular buffer and the block becomes disowned (see grd) |
| _gc_affinity_time | specifies interval minutes for reamstering |
| _gc_affinity_limit | defines the number of times a instance access the resource before remastering |
| _gc_affinity_minimum | defines the minimum number of times a instance access the resource before remastering |
| _lm_file_affinity | disables dynamic remastering for the objects belonging to those files |
| _lm_dynamic_remastering | enable or disable remastering |
| _gc_defer_time | define the time by which an instance deferred downgrading a lock (see Cache Fusion) |
| _lgwr_async_broadcast | change the SCN boardcast method (see troubleshooting) |
September 1, 2017
RAC Useful Views And Tables
Installation/Configurations10gInstallation/Configurations11gInstallation/Configurations12cOracle Database Material
RAC Useful Views And Tables
|
GCS and Cache Fusion Diagnostics |
|
| v$cache | contains information about every cached block in the buffer cache |
| v$cache_transfer | contains information from the block headers in SGA that have been pinged at least once |
| v$instance_cache_transfer | contains information about the transfer of cache blocks through the interconnect |
| v$cr_block_server | contains statistics about CR block transfer across the instances |
| v$current_block_server | contains statistics about current block transfer across the instances |
| v$gc_element | contains one-to-one information for each global cache resource used by the buffer cache |
|
GES diagnostics |
|
| v$lock | contains information about locks held within a database and outstanding requests for locks and latches |
| v$ges_blocking_enqueue | contains information about locks that are being blocked or blocking others and locks that are known to the lock manager |
| v$enqueue_statistics | contains details about enqueue statistics in the instance |
| v$resource_limits | display enqueue statistics |
| v$locked_object | contains information about DML locks acquired by different transactions in databases with their mode held |
| v$ges_statistics | contains miscellaneous statistics for GES |
| v$ges_enqueue | contains information about all locks known to the lock manager |
| v$ges_convert_local | contains information about all local GES operations |
| v$ges_convert_remote | contains information about all remote GES operations |
| v$ges_resource | contains information about all resources known to the lock manager |
| v$ges_misc | contains information about messaging traffic information |
| v$ges_traffic_controller | contains information about the message ticket usage |
|
Dynamic Resource Remastering |
|
| v$hvmaster_info | contains information about current and previous master instances of GES resources in relation to hash value ID of resource |
| v$gcshvmaster_info | the same as above but globally |
| v$gcspfmaster_info | conatins information about current and previous masters about GCS resources belonging to files mapped to a particular master, including the number of times the resource has remastered |
|
Cluster Interconnect |
|
| v$cluster_interconnects | contains information about interconnects that are being used for cluster communication |
| v$configured_interconnects | same as above but also contains interconnects that AC is aware off that are not being used |
|
Miscellanous |
|
| v$service | services running on an instance |
| x$kjmsdp | display LMS daemon statistics |
| x$kjmddp | display LMD daemon statistics |
September 1, 2017
RAC Files and Directories
Errors/Workarounds10gErrors/Workarounds11gErrors/Workarounds12cOracle Database Material
RAC Files and Directories
$ORA_CRS_HOME/cdata/<cluster_name> |
OCR backups (default location) |
$ORA_HOME/log/<hostname>/client/ocrconfig_<pid>.log |
OCR command log file |
$ORA_CRS_HOME/crs/log |
contains trace files for the CRS resources |
$ORA_CRS_HOME/crs/init |
contains trace files for the CRS daemon during startup, a good place to start |
$ORA_CRS_HOME/css/log |
contains cluster reconfigurations, missed check-ins, connects and disconnects from the client CSS listener. Look here to obtain when reboots occur |
$ORA_CRS_HOME/css/init |
contains core dumps from the cluster synchronization service daemon (OCSd) |
$ORA_CRS_HOME/evm/log |
logfiles for the event volume manager and eventlogger daemon |
$ORA_CRS_HOME/evm/init |
pid and lock files for EVM |
$ORA_CRS_HOME/srvm/log |
logfiles for Oracle Cluster Registry (OCR) |
$ORA_CRS_HOME/log |
log fles for Oracle clusterware which contains diagnostic messages at the Oracle cluster level |
September 1, 2017
RAC Acronyms in Used
APPS DBAInstallation/Configurations10gInstallation/Configurations11gInstallation/Configurations12cOracle Database Material
Real Application Cluster Acronyms
GCS |
Global Cache Services | in memory database containing current locks and awaiting locks, also known as PCM |
GES |
Global Enqueue Services | coordinates the requests of all global enqueues uses the GCS, also known as non-PCM |
GRD |
Global Resource Directory | all resources available to the cluster (formed and managed by GCS and GES), see GRDfor more details |
GRM |
Global Resource Manager | helps to coordinate and communicate the locks requests between Oracle processes |
GSD |
Global Services Daemon | runs on each node with one GSD process per node. The GSD coordinates with the cluster manager to receive requests from clients such as the DBCA, EM, and the SRVCTL utility to execute administrative job tasks such as instance startup or shutdown. The GSD is not an Oracle instance background process and is therefore not started with the Oracle instance |
PCM (IDLM) |
Parallel Cache Management | formly know as (integrated) Distributed Lock Manager, its another name for GCS |
Resource |
n/a | it is a identifiable entity it basically has a name or a reference, it can be a area in memory, a disk file or an abstract entity |
Resource (Global) |
n/a | a resource that can be accessed by all the nodes within the cluster examples would be the following
Data Buffer Cache Block Transaction Enqueue Database Data Structures |
LVB |
Lock Value Block | contains a small amount of data regarding the lock |
TRFC |
Traffic Controller | controls the DLM traffic between instances (messaging tickets) |